Powerscourt Estate has repotted up to 80 percent of its boxwood plants to prevent the moth from invading, says garden manager Alex Slazenger. Powerscourt Estate gardeners have not recorded any boxwood moths or their destructive larvae on the property, but they describe it as “inevitable” due to climate change.
The box moth is native to East Asia but was first discovered in mainland Europe in 2007 and in Ireland in 2017. It is presumed to be carried on infected boxwood plants.
The boxwood beetle has breeding habitats throughout the UK and is well adapted to the Irish environment. The first confirmed suspect specimen in Ireland was caught in a moth trap in Waterford. Since then the moth has been found in Dublin, Cork, Waterford, Wicklow, Laois, Kildare, Clare, Donegal, Antrim and Down.
The larvae feed on both the leaves and bark of boxwood, killing the plant, which has no natural predators in the country that can control it.
At Powerscourt Estate, 500 metres of boxwood has been replaced with a dwarf yew hedge, and gardeners are recommending that no more boxwood be planted.
Wicklow Farm has taken this approach despite not having box flies in its gardens as it aims to be more sustainable, and the chemicals they use to get rid of them are highly toxic. “Box flies are rampant around Dublin. If they were there we wouldn't be spraying chemicals,” Mr Slazenger said.
Some of the existing boxwood trees on the property have been killed by boxwood wilt, a resistant fungal disease.
Slazenger said climate change is affecting the fungal diseases and pests found on farms. “We used to rely on very cold winters to get rid of blight.”
Powerscourt Estate has taken several “precautionary measures” to prevent an infestation by box moths, with Mr Slazenger highlighting that the moths can “wipe out an entire plant overnight”.
Powerscourt is the first Irish destination to be certified as a leading Sustainable Travel Ireland tourist destination. “We're looking at the gardens to see what's right for the future and to reduce our use of chemicals,” Mr Slazenger said.
:quality(70)/cloudfront-eu-central-1.images.arcpublishing.com/irishtimes/MU6ONOQUIVE57K7B5XPYLINK5E.jpg)
The garden's future is explained by its adaptation to the climate, as gardeners create gardens that adapt to the climate. “We're selecting species that will survive,” Slazenger says. “New diseases and pests aren't new; they've just migrated across the planet as the climate changes.”
Over the past few years, in some locations on the Office of Public Works, such as St Stephen's Green, boxwood wilt or boxwood blight, has also affected boxwood hedges, which have been replaced by other varieties such as yew and euonymus.
